Dicing tape-integrated film for semiconductor back surface, and process for producing semiconductor device

ABSTRACT

The present invention relates to a dicing tape-integrated film for semiconductor back surface including: a dicing tape including a base material and a pressure-sensitive adhesive layer laminated in this order, and a film for semiconductor back surface provided on the pressure-sensitive adhesive layer of the dicing tape, where the pressure-sensitive adhesive layer has a thickness of from 20 μm to 40 μm.

FIELD OF THE INVENTION

The present invention relates to a dicing tape-integrated film forsemiconductor back surface and to a process for producing asemiconductor device. The film for semiconductor back surface is usedfor protecting the back surface of a semiconductor element such as asemiconductor chip and for enhancing the strength thereof.

BACKGROUND OF THE INVENTION

Recently, thinning and miniaturization of a semiconductor device and itspackage have been increasingly demanded. Therefore, as the semiconductordevice and its package, flip chip type semiconductor devices in which asemiconductor element such as a semiconductor chip is mounted (flipchip-connected) on a substrate by means of flip chip bonding have beenwidely utilized. In such flip chip connection, a semiconductor chip isfixed to a substrate in a form where a circuit face of the semiconductorchip is opposed to an electrode-formed face of the substrate. In such asemiconductor device or the like, there may be a case where the backsurface of the semiconductor chip is protected with a protective film toprevent the semiconductor chip from damaging or the like (see, PatentDocument 1 to 3).

Patent Document 1: JP-A-2008-166451

Patent Document 2: JP-A-2008-006386

Patent Document 3: JP-A-2007-261035

However, in order to protect a back surface of a semiconductor chip bythe protective film, it is necessary to add a new step for attaching theprotective film to the back surface of the semiconductor chip obtainedin a dicing step. As a result, the number of steps increases andproduction cost and the like increase. Accordingly, for the purpose ofreducing the production cost, the present inventors have developed adicing tape-integrated film for semiconductor back surface and filed anapplication therefor (not yet published at the time of filing thepresent application). The dicing tape-integrated film for semiconductorback surface has a structure including a dicing tape having a basematerial and a pressure-sensitive adhesive layer on the base material,and a film for flip chip type semiconductor back surface formed on thepressure-sensitive adhesive layer of the dicing tape.

At the production of the semiconductor device, the dicingtape-integrated film for semiconductor back surface is used as follows.First, a semiconductor wafer is attached onto the film for flip chiptype semiconductor back surface in the dicing tape-integrated film forsemiconductor back surface. Next, the semiconductor wafer is diced toform a semiconductor element. Subsequently, the semiconductor element ispeeled from the pressure-sensitive adhesive layer of the dicing tape andpicked up together with the film for flip chip type semiconductor backsurface and then the semiconductor element is flip chip-connected ontoan adherend such as a substrate. Consequently, a flip chip typesemiconductor device is obtained.

For the semiconductor wafer dicing, widely employed is a so-calledfull-cut process of dicing to a depth reaching the base material layerof the dicing tape over the film for semiconductor back surface as thecutting depth of the dicing blade. Heretofore, taking the matter intoconsideration that the thickness of the pressure-sensitive adhesivelayer is 10 μm or so and taking the dicing machine accuracy intoconsideration, much employed is a method of evading the failure in thedicing step by dicing to the base material over the pressure-sensitiveadhesive layer in full-cut operation for taking production margin.Accordingly, the subsequent picking-up process enables integrallypeeling the semiconductor chip along with the film for semiconductorback surface, without requiring any additional step or operation ofcutting the film for semiconductor back surface.

However, cutting to the base material produces base material-derivedcutting dust, and the cutting dust adheres to the side of the dicedsemiconductor chips and may form a deposit of so-called burr around thechips. When the semiconductor chip with such burr is built in asemiconductor device, it may cause interconnection failure to adherendsand contamination of substrate circuits, which may result in loweringthe reliability of semiconductor devices.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the foregoingproblems, and an object thereof is to provide a dicing tape-integratedfilm for semiconductor back surface which is capable of exhibiting gooddicing aptitude and capable of preventing the generation of burr aroundthe semiconductor chips to be produced by dicing of a semiconductorwafer, thereby making it possible to produce semiconductor devices ofhigh reliability with improving the production yield, and to provide aprocess for producing semiconductor devices.

The present inventors have assiduously studied for the purpose ofsolving the existing problems and, as a result, have found that, byemploying the following constitution, a dicing tape-integrated film forsemiconductor back surface having good dicing aptitude and capable ofpreventing the generation of burr around semiconductor chips can beprovided, and have completed the present invention.

Namely, the present invention relates to a dicing tape-integrated filmfor semiconductor back surface (herein after may be referred as“integrated film”) which includes: a dicing tape including a basematerial and a pressure-sensitive adhesive layer laminated in thisorder, and a film for semiconductor back surface provided on thepressure-sensitive adhesive layer of the dicing tape, in which thepressure-sensitive adhesive layer has a thickness of from 20 μm to 40μm.

The integrated film comprises a pressure-sensitive adhesive layer havinga thickness of from 20 μm to 40 μm, and can therefore fully secure theproduction margin by cutting to the pressure-sensitive adhesive layer indicing, though the production margin has heretofore been secured bycutting to the base material in dicing. Accordingly, the cutting dust tobe generated by cutting to reach the base material can be prevented. Asa result, the film can contribute toward producing semiconductor devicesof high reliability by preventing the generation of burr aroundsemiconductor chips while keeping the good dicing property thereof. Whenthe thickness of the pressure-sensitive adhesive layer is less than 20μm, then the production margin by the pressure-sensitive adhesive layerwould be insufficient and cutting the film may reach the base materialthereby to inevitably produce the cutting dust from the base material,therefore resulting in the generation of burr around semiconductorchips. On the other hand, when the thickness of the pressure-sensitiveadhesive layer is more than 40 μm, then the flexibility and thetackiness of the pressure-sensitive adhesive layer may be too high andtherefore the ability thereof to hold and fix semiconductor wafers maylower with the result that the semiconductor chips may be broken orcracked during dicing and the once cut semiconductor chips may blocktogether.

When the thickness of the pressure-sensitive adhesive layer is taken asx and the thickness of the film for semiconductor back surface is takenas y, it is preferable that the ratio x/y is from 1 to 4. When the ratiox/y is from 1 to 4, then the adhesive force of the pressure-sensitiveadhesive layer may be readily regulated within a suitable range and thepressure-sensitive adhesive layer can secure good peeling strength tosuch a degree that, between the pressure-sensitive adhesive layer andthe film for semiconductor back surface, the holding force in dicing andthe peeling easiness in picking up can be well balanced.

When the thickness of the dicing tape is taken as z and the thickness ofthe film for semiconductor back surface is taken as y, it is preferablethat the ratio z/y is from 1.5 to 25. When the ratio z/y is from 1.5 to25, then the film for semiconductor back surface may be prevented frombeing so thin as to worsen its picking-up property, and on the otherhand, the film for semiconductor back surface may be prevented frombeing so thick as to produce burr that is derived from the film forsemiconductor back surface, around semiconductor chips in dicing.

The present invention also provides a process for producing asemiconductor device using the above-mentioned dicing tape-integratedfilm for semiconductor back surface, the process including: attaching asemiconductor wafer onto the film for semiconductor back surface of thedicing tape-integrated film for semiconductor back surface, dicing thesemiconductor wafer to form a semiconductor chip in which a cuttingdepth is so controlled as to fall within a range overstepping one sideof the pressure-sensitive adhesive layer that faces the film forsemiconductor back surface and not reaching the other side of thepressure-sensitive adhesive layer that faces the base material, peelingthe semiconductor chip from the pressure-sensitive adhesive layer of thedicing tape together with the film for semiconductor back surface, andflip chip-connecting the semiconductor chip onto an adherend.

In the production process, the integrated film in which the thickness ofthe pressure-sensitive adhesive layer is from 20 μm to 40 μm is used,and the cutting depth with the dicing blade is defined to fall within apredetermined range in the dicing step. Therefore, the productionmargin, which is heretofore secured by cutting to reach the basematerial in dicing, can be well secured by cutting to reach thepressure-sensitive adhesive layer. Accordingly, the generation of thecutting dust to be caused by cutting to reach the base material can beprevented, and as a result, semiconductor devices of high reliabilitycan be efficiently produced with preventing the generation of burraround semiconductor chips and with keeping the good dicing property inthe process.

Preferably, in the dicing, the cutting depth is so controlled as to fallwithin a range of from 10% to 70% of the thickness of thepressure-sensitive adhesive layer from the side of thepressure-sensitive adhesive layer that faces the film for semiconductorback surface. When the cutting depth is controlled to fall within theabove-mentioned range, then the cutting to reach the base material maybe prevented even though the cutting depth accuracy fluctuation ofvarious dicing machines is taken into consideration, and therefore theproduction process of the invention can readily accept various changesin production lines with preventing deep cutting to reach the basematerial. In addition, the production process of the invention can wellsecure the production margin in dicing and can therefore preventgeneration of various failures such as dicing failure, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional schematic view showing one embodiment of adicing tape-integrated film for semiconductor back surface of theinvention.

FIGS. 2A to 2D are cross-sectional schematic views showing oneembodiment of a process for producing a semiconductor device using adicing tape-integrated film for semiconductor back surface of theinvention.

DESCRIPTION OF REFERENCE NUMERALS AND SIGNS

-   -   1 Dicing Tape-Integrated Film for Semiconductor Back Surface    -   2 Film for Semiconductor Back Surface    -   3 Dicing Tape    -   31 Base Material    -   32 Pressure-Sensitive Adhesive Layer    -   33 Part Corresponding to Semiconductor Wafer-Attaching Part    -   4 Semiconductor Wafer    -   5 Semiconductor Chip    -   51 Bump Formed on the Circuit Face Side of Semiconductor Chip 5    -   6 Adherend    -   61 Conductive Material for Conjunction Attached to Connection        Pad of Adherend 6

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention are described with reference toFIG. 1 but the invention is not restricted to these embodiments. FIG. 1is a cross-sectional schematic view showing one embodiment of a dicingtape-integrated film for semiconductor back surface according to thepresent embodiment. Incidentally, in the figures in the presentspecification, parts that are unnecessary for the description are notgiven, and there are parts shown by magnifying, minifying, etc. in orderto make the description easy.

(Dicing Tape-Integrated Film for Semiconductor Back Surface)

As shown in FIG. 1, the dicing tape-integrated film for semiconductorback surface 1 (hereinafter sometimes also referred to as “integratedfilm”, “dicing tape-integrated semiconductor back surface protectivefilm”, “film for semiconductor back surface with dicing tape”, or“semiconductor back surface protective film with dicing tape”) has aconfiguration including: the dicing tape 3 including thepressure-sensitive adhesive layer 32 formed on the base material 31,and, as formed on the pressure-sensitive adhesive layer 32, the film forsemiconductor back surface 2 suitable for flip chip type semiconductors.Also as shown in FIG. 1, the dicing tape-integrated film forsemiconductor back surface of the invention may be so designed that thefilm for semiconductor back surface 2 (hereinafter sometimes referred toas “semiconductor back surface protective film”) is formed only on thepart 33 corresponding to the semiconductor wafer-attaching part;however, the film for semiconductor back surface may be formed over thewhole surface of the pressure-sensitive adhesive layer 32, or the filmfor semiconductor back surface may be formed on the part larger than thepart 33 corresponding to the semiconductor wafer-attaching part butsmaller than the whole surface of the pressure-sensitive adhesive layer32. Incidentally, the surface of the film for semiconductor back surface2 (surface to be attached to the back surface of wafer) may be protectedwith a separator or the like until the film is attached to wafer backsurface.

In the integrated film 1, the thickness of the pressure-sensitiveadhesive layer 32 is from 20 μm to 40 μm. Accordingly, the productionmargin in dicing can be well secured by cutting to reach thepressure-sensitive adhesive layer. In addition, the generation ofcutting dust to be caused by cutting to reach the base material can beprevented and, as a result, the film can contribute toward production ofsemiconductor devices of high reliability while keeping the good dicingproperty thereof and while preventing the generation of burr aroundsemiconductor chips. When the thickness of the pressure-sensitiveadhesive layer is less than 20 μm, then the production margin with thepressure-sensitive adhesive layer will be insufficient and the film maybe cut to reach the base material, and if so, cutting dust may begenerated from the base material, and as a result, burr may be generatedaround semiconductor chips. On the other hand, when the thickness of thepressure-sensitive adhesive layer is more than 40 μm, then theflexibility and the tackiness of the pressure-sensitive adhesive layermay be too high and therefore the ability thereof to hold and fixsemiconductor wafers may lower with the result that the semiconductorchips may be broken or cracked during dicing and the once cutsemiconductor chips may block together.

The thickness of the pressure-sensitive adhesive layer 32 may be good tobe from 20 μm to 40 μm. The uppermost limit of the thickness of thepressure-sensitive adhesive layer is preferably 38 μm, more preferably35 μm. The lowermost limit of the thickness of the pressure-sensitiveadhesive layer is preferably 23 μm, more preferably 25 μm. Thepressure-sensitive adhesive layer 32 may be either a single layer or amultilayer.

Not specifically defined, when the thickness of the pressure-sensitiveadhesive layer 32 is taken as x and the thickness of the film forsemiconductor back surface 2 is taken as y, the ratio x/y is preferablyfrom 1 to 4, more preferably from 1.1 to 3.9, even more preferably from1.2 to 3.8. When the ratio x/y falls within the above range, then thepressure-sensitive adhesive layer may be given a suitable adhesive forceand the peeling strength between the pressure-sensitive adhesive layerand the film for semiconductor back surface can be a suitable one, andthe holding force in dicing and the peeling easiness in picking up canbe well balanced.

Also not specifically defined, when the thickness of the dicing tape 3is taken as z and the thickness of the film for semiconductor backsurface 2 is taken as y, the ratio z/y is preferably from 1.5 to 25,more preferably from 1.6 to 24, even more preferably from 1.7 to 23.When the ratio z/y falls within the above range, then the film forsemiconductor back surface may be prevented from being so thin as toworsen its picking-up property, and on the other hand, the film forsemiconductor back surface may be prevented from being so thick as toproduce burr that is derived from the film for semiconductor backsurface, around semiconductor chips in dicing.

(Film for Semiconductor Back Surface)

The film for semiconductor back surface 2 has a film shape. The film forsemiconductor back surface 2 is usually in an uncured state (including asemi-cured state) in the embodiment of the dicing tape-integrated filmfor semiconductor back surface as a product and is thermally cured afterthe dicing tape-integrated film for semiconductor back surface isattached to the semiconductor wafer.

Preferably, the film for semiconductor back surface 2 is formed of atleast a thermosetting resin, more preferably formed of at least athermosetting resin and a thermoplastic resin. A thermalcuring-accelerating catalyst may be contained in the resin thatconstitutes the film for semiconductor back surface 2. When the film forsemiconductor back surface 2 is formed of at least a thermosettingresin, the film can effectively exhibit its adhesive function.

Examples of the thermoplastic resin include natural rubber, butylrubber, isoprene rubber, chloroprene rubber, an ethylene-vinyl acetatecopolymer, an ethylene-acrylic acid copolymer, an ethylene-acrylic acidester copolymer, a polybutadiene resin, a polycarbonate resin, athermoplastic polyimide resin, a polyamide resin such as 6-nylon and6,6-nylon, a phenoxy resin, an acrylic resin, a saturated polyesterresin such as PET (polyethylene terephthalate) or PBT (polybutyleneterephthalate), a polyamideimide resin, or a fluorine resin. Thethermoplastic resin may be employed singly or in a combination of two ormore kinds. Among these thermoplastic resins, an acrylic resincontaining a small amount of ionic impurities, having high heatresistance and capable of securing reliability of a semiconductorelement is especially preferable.

The acrylic resins are not particularly restricted, and examples thereofinclude polymers containing one kind or two or more kinds of esters ofacrylic acid or methacrylic acid having a straight chain or branchedalkyl group having 30 or less carbon atoms, preferably 4 to 18 carbonatoms, more preferably 6 to 10 carbon atoms, and especially 8 or 9carbon atoms as component(s). Namely, in the invention, the acrylicresin has a broad meaning also including a methacrylic resin. Examplesof the alkyl group include a methyl group, an ethyl group, a propylgroup, an isopropyl group, an n-butyl group, a t-butyl group, anisobutyl group, a pentyl group, an isopentyl group, a hexyl group, aheptyl group, a 2-ethylhexyl group, an octyl group, an isooctyl group, anonyl group, an isononyl group, a decyl group, an isodecyl group, anundecyl group, a dodecyl group (lauryl group), a tridecyl group, atetradecyl group, a stearyl group, and an octadecyl group.

Moreover, other monomers for forming the acrylic resins (monomers otherthan the alkyl esters of acrylic acid or methacrylic acid in which thealkyl group is one having 30 or less carbon atoms) are not particularlyrestricted, and examples thereof include carboxyl group-containingmonomers such as acrylic acid, methacrylic acid, carboxylethyl acrylate,carboxylpentyl acrylate, itaconic acid, maleic acid, fumaric acid, andcrotonic acid; acid anhydride monomers such as maleic anhydride anditaconic anhydride; hydroxyl group-containing monomers such as2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate,8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate,12-hydroxylauryl (meth)acrylate, and(4-hydroxymethylcyclohexyl)-methylacrylate; sulfonic acidgroup-containing monomers such as styrenesulfonic acid, allylsulfonicacid, 2-(meth)acrylamido-2-methylpropanesulfonic acid,(meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, and(meth)acryloyloxynaphthalenesulfonic acid; and phosphoric acidgroup-containing monomers such as 2-hydroxyethylacryloyl phosphate. Inthis regard, the (meth)acrylic acid means acrylic acid and/ormethacrylic acid, (meth)acrylate means acrylate and/or methacrylate,(meth)acryl means acryl and/or methacryl, etc., which shall be appliedover the whole specification.

Moreover, examples of the thermosetting resin include, in addition to anepoxy resin and a phenol resin, an amino resin, an unsaturated polyesterresin, a polyurethane resin, a silicone resin and a thermosettingpolyimide resin. The thermosetting resin may be employed singly or in acombination of two or more kinds. As the thermosetting resin, an epoxyresin containing only a small amount of ionic impurities which corrode asemiconductor element is suitable. Also, the phenol resin is suitablyused as a curing agent of the epoxy resins.

The epoxy resin is not particularly restricted and, for example, adifunctional epoxy resin or a polyfunctional epoxy resin such as abisphenol A type epoxy resin, a bisphenol F type epoxy resin, abisphenol S type epoxy resin, a brominated bisphenol A type epoxy resin,a hydrogenated bisphenol A type epoxy resin, a bisphenol AF type epoxyresin, a biphenyl type epoxy resin, a naphthalene type epoxy resin, afluorene type epoxy resin, a phenol novolak type epoxy resin, ano-cresol novolak type epoxy resin, a trishydroxyphenylmethane type epoxyresin and a tetraphenylolethane type epoxy resin, or an epoxy resin suchas a hydantoin type epoxy resin, a trisglycidylisocyanurate type epoxyresin or a glycidylamine type epoxy resin may be used.

As the epoxy resin, among those exemplified above, a novolak type epoxyresin, a biphenyl type epoxy resin, a trishydroxyphenylmethane typeepoxy resin, and a tetraphenylolethane type epoxy resin are preferable.This is because these epoxy resins have high reactivity with a phenolresin as a curing agent and are superior in heat resistance and thelike.

Furthermore, the above-mentioned phenol resin acts as a curing agent ofthe epoxy resin, and examples thereof include novolak type phenol resinssuch as phenol novolak resins, phenol aralkyl resins, cresol novolakresins, tert-butylphenol novolak resins, and nonyiphenol novolak resins;resol type phenol resins; and polyoxystyrenes such as poly-p-oxystyrene.The phenol resin may be employed singly or in a combination of two ormore kinds. Among these phenol resins, phenol novolak resins and phenolaralkyl resins are especially preferable. This is because connectionreliability of the semiconductor device can be improved.

The mixing ratio of the epoxy resin to the phenol resin is preferablymade, for example, such that the hydroxyl group in the phenol resinbecomes 0.5 to 2.0 equivalents per equivalent of the epoxy group in theepoxy resin component. It is more preferably 0.8 to 1.2 equivalents.That is, when the mixing ratio becomes outside the range, a curingreaction does not proceed sufficiently, and the characteristics of theepoxy resin cured product tends to deteriorate.

The content of the thermosetting resin is preferably from 5% by weightto 90% by weight of all the resin components in the film forsemiconductor back surface 2, more preferably from 10% by weight to 85%by weight, even more preferably from 15% by weight to 80% by weight.When the content is 5% by weight or more, then the thermosettingshrinkage may be readily controlled to be 2% by volume or more. Inaddition, in thermally curing the encapsulating resin, the film forsemiconductor back surface 2 may be fully thermo-cured so as to besurely adhered and fixed to the back surface of a semiconductor elementto give a flip chip type semiconductor device with no peeling failure.On the other hand, when the content is 90% by weight or less, then thepackage (PKG, flip chip type semiconductor device) may be prevented fromwarping.

Not specifically defined, the thermal curing-accelerating catalyst forepoxy resins and phenolic resins may be suitably selected from knownthermal curing-accelerating catalysts. One or more thermalcuring-accelerating catalysts may be used here either singly or ascombined. As the thermal curing-accelerating catalyst, for example, anamine-based curing-accelerating catalyst, a phosphorus-basedcuring-accelerating catalyst, an imidazole-based curing-acceleratingcatalyst, a boron-based curing-accelerating catalyst, or aphosphorus-boron-based curing-accelerating catalyst can be used.

The film for semiconductor back surface is particularly suitably formedof a resin composition containing an epoxy resin and a phenolic resin ora resin composition containing an epoxy resin, a phenolic resin, and anacrylic resin. Since these resins contain only a small amount of ionicimpurities and have high heat resistance, reliability of semiconductorelements can be secured.

It is important that the film for semiconductor back surface 2 hasadhesiveness (close adhesiveness) to the back surface(non-circuit-formed face) of semiconductor wafer. The film forsemiconductor back surface 2 can be, for example, formed of a resincomposition containing an epoxy resin as a thermosetting resincomponent. In case where the film for semiconductor back surface 2 iscured beforehand to some degree, at its preparation, it is preferable toadd a polyfunctional compound capable of reacting with the functionalgroup or the like at the molecular chain end of the polymer as acrosslinking agent. Thereby, adhesive characteristics under hightemperature can be enhanced and improvement of the heat resistance ofthe film can be achieved.

The adhesive force of the film for semiconductor back surface tosemiconductor wafer (23° C., peeling angle of 180 degrees, peeling rateof 300 mm/min) is preferably within a range of from 0.5 N/20 mm to 15N/20 mm, more preferably from 0.7 N/20 mm to 10 N/20 mm. When theadhesive force is at least 0.5 N/20 mm, then the film can be adhered tosemiconductor wafer and semiconductor element with excellentadhesiveness and is free from film swelling or the like adhesionfailure. In addition, in dicing of semiconductor wafer, the chips can beprevented from flying out. On the other hand, when the adhesive force isat most 15 N/20 mm, then it facilitates peeling from the dicing tape.

The crosslinking agent is not particularly restricted and knowncrosslinking agents can be used. Specifically, for example, not onlyisocyanate-based crosslinking agents, epoxy-based crosslinking agents,melamine-based crosslinking agents, and peroxide-based crosslinkingagents but also urea-based crosslinking agents, metal alkoxide-basedcrosslinking agents, metal chelate-based crosslinking agents, metalsalt-based crosslinking agents, carbodiimide-based crosslinking agents,oxazoline-based crosslinking agents, aziridine-based crosslinkingagents, amine-based crosslinking agents, and the like may be mentioned.As the crosslinking agent, an isocyanate-based crosslinking agent or anepoxy-based crosslinking agent is suitable. The crosslinking agent maybe employed singly or in a combination of two or more kinds.

Examples of the isocyanate-based crosslinking agents include loweraliphatic polyisocyanates such as 1,2-ethylene diisocyanate,1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; alicyclicpolyisocyanates such as cyclopentylene diisocyanate, cyclohexylenediisocyanate, isophorone diisocyanate, hydrogenated tolylenediisocyanate, and hydrogenated xylylene diisocyanate; and aromaticpolyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylenediisocyanate, 4,4′-diphenylmethane diisocyanate, and xylylenediisocyanate. In addition, a trimethylolpropane/tolylene diisocyanatetrimer adduct [a trade name “COLONATE L” manufactured by NipponPolyurethane Industry Co., Ltd.], a trimethylolpropane/hexamethylenediisocyanate trimer adduct [a trade name “COLONATE HL” manufactured byNippon Polyurethane Industry Co., Ltd.], and the like are also used.Moreover, examples of the epoxy-based crosslinking agents includeN,N,N′,N′-tetraglycidyl-m-xylenediamine, diglycidylaniline,1,3-bis(N,N-glycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidylether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidylether, propylene glycol diglycidyl ether, polyethylene glycol diglycidylether, polypropylene glycol diglycidyl ether, sorbitol polyglycidylether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether,polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether,trimethylolpropnane polyglycidyl ether, adipic acid diglycidyl ester,o-phthalic acid diglycidyl ester,triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcin diglycidyl ether,and bisphenol-S-diglycidyl ether, and also epoxy-based resins having twoor more epoxy groups in the molecule.

The amount of the crosslinking agent to be used is not particularlyrestricted and can be appropriately selected depending on the degree ofthe crosslinking. Specifically, it is preferable that the amount of thecrosslinking agent to be used is usually 7 parts by weight or less (forexample, 0.05 to 7 parts by weight) based on 100 parts by weight of thepolymer component (particularly, a polymer having a functional group atthe molecular chain end). When the amount of the crosslinking agent islarger than 7 parts by weight based on 100 parts by weight of thepolymer component, the adhesive force is lowered, so that the case isnot preferred. From the viewpoint of improving the cohesive force, theamount of the crosslinking agent is preferably 0.05 parts by weight ormore based on 100 parts by weight of the polymer component.

In the invention, instead of the use of the crosslinking agent ortogether with the use of the crosslinking agent, it is also possible toperform a crosslinking treatment by irradiation with an electron beam,UV light, or the like.

The film for semiconductor back surface is preferably colored. Thereby,an excellent laser marking property and an excellent appearance propertycan be exhibited, and it becomes possible to make a semiconductor devicehaving a value-added appearance property. As above, since the coloredfilm for semiconductor back surface has an excellent marking property,marking can be performed to impart various kinds of information such asliteral information and graphical information to the face on thenon-circuit side of the semiconductor element or a semiconductor deviceusing the semiconductor element by utilizing any of various markingmethods such as a printing method and a laser marking method through thefilm of semiconductor back surface. Particularly, by controlling thecolor of coloring, it becomes possible to observe the information (forexample, literal information and graphical information) imparted bymarking with excellent visibility. Moreover, when the film forsemiconductor back surface is colored, the dicing tape and the film forsemiconductor back surface can be easily distinguished from each other,so that workability and the like can be enhanced. Furthermore, forexample, as a semiconductor device, it is possible to classify productsthereof by using different colors. In the case where the film forsemiconductor back surface is colored (the case where the film isneither colorless nor transparent), the color shown by coloring is notparticularly limited but, for example, is preferably dark color such asblack, blue or red color, and black color is especially suitable.

In the present embodiment, dark color basically means a dark colorhaving L*, defined in L*a*b* color space, of 60 or smaller (0 to 60),preferably 50 or smaller (0 to 50), and more preferably 40 or smaller (0to 40).

Moreover, black color basically means a black-based color having L*,defined in L*a*b* color space, of 35 or smaller (0 to 35), preferably 30or smaller (0 to 30), and more preferably 25 or smaller (0 to 25). Inthis regard, in the black color, each of a* and b*, defined in theL*a*b* color space, can be suitably selected according to the value ofL*. For example, both of a* and b* are within the range of preferably−10 to 10, more preferably −5 to 5, and further preferably −3 to 3(particularly 0 or about 0).

In the present embodiment, L*, a*, and b* defined in the L*a*b* colorspace can be determined by a measurement with a color difference meter(a trade name “CR-200” manufactured by Minolta Ltd; color differencemeter). The L*a*b* color space is a color space recommended by theCommission Internationale de l'Eclairage (CIE) in 1976, and means acolor space called CIE1976(L*a*b*) color space. Also, the L*a*b* colorspace is defined in Japanese Industrial Standards in JIS Z8729.

At coloring of the film for semiconductor back surface, according to anobjective color, a colorant (coloring agent) can be used. As such acolorant, various dark-colored colorants such as black-coloredcolorants, blue-colored colorants, and red-colored colorants can besuitably used and black-colored colorants are more suitable. Thecolorant may be any of pigments and dyes. The colorant may be employedsingly or in combination of two or more kinds. In this regard, as thedyes, it is possible to use any forms of dyes such as acid dyes,reactive dyes, direct dyes, disperse dyes, and cationic dyes. Moreover,also with regard to the pigments, the form thereof is not particularlyrestricted and can be suitably selected and used among known pigments.

In particular, when a dye is used as a colorant, the dye becomes in astate that it is homogeneously or almost homogeneously dispersed bydissolution in the film for semiconductor back surface, so that the filmfor semiconductor back surface (as a result, the dicing tape-integratedfilm for semiconductor back surface) having a homogeneous or almosthomogeneous color density can be easily produced. Accordingly, when adye is used as a colorant, the film for semiconductor back surface inthe dicing tape-integrated film for semiconductor back surface can havea homogeneous or almost homogeneous color density and can enhance amarking property and an appearance property.

The black-colored colorant is not particularly restricted and can be,for example, suitably selected from inorganic black-colored pigments andblack-colored dyes. Moreover, the black-colored colorant may be acolorant mixture in which a cyan-colored colorant (blue-green colorant),a magenta-colored colorant (red-purple colorant), and a yellow-coloredcolorant (yellow colorant) are mixed. The black-colored colorant may beemployed singly or in a combination of two or more kinds. Of course, theblack-colored colorant may be used in combination with a colorant of acolor other than black.

Specific examples of the black-colored colorant include carbon black(such as furnace black, channel black, acetylene black, thermal black,or lamp black), graphite, copper oxide, manganese dioxide, azo-typepigments (such as azomethine azo black), aniline black, perylene black,titanium black, cyanine black, active charcoal, ferrite (such asnon-magnetic ferrite or magnetic ferrite), magnetite, chromium oxide,iron oxide, molybdenum disulfide, a chromium complex, a composite oxidetype black pigment, and an anthraquinone type organic black pigment.

In the invention, as the black-colored colorant, black-colored dyes suchas C.I. Solvent Black 3, 7, 22, 27, 29, 34, 43, 70, C.I. Direct Black17, 19, 22, 32, 38, 51, 71, C.I. Acid Black 1, 2, 24, 26, 31, 48, 52,107, 109, 110, 119, 154, and C.I. Disperse Black 1, 3, 10, 24;black-colored pigments such as C.I. Pigment Black 1, 7; and the like canalso be utilized.

As such black-colored colorants, for example, a trade name “Oil BlackBY”, a trade name “Oil Black BS”, a trade name “Oil Black HBB”, a tradename “Oil Black 803”, a trade name “Oil Black 860”, a trade name “OilBlack 5970”, a trade name “Oil Black 5906”, a trade name “Oil Black5905” (manufactured by Orient Chemical Industries Co., Ltd.), and thelike are commercially available.

Examples of colorants other than the black-colored colorant includecyan-colored colorants, magenta-colored colorants, and yellow-coloredcolorants. Examples of the cyan-colored colorants include cyan-coloreddyes such as C.I. Solvent Blue 25, 36, 60, 70, 93, 95; C.I. Acid Blue 6and 45; cyan-colored pigments such as C.I. Pigment Blue 1, 2, 3, 15,15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 16, 17, 17:1, 18, 22, 25, 56, 60,63, 65, 66; C.I. Vat Blue 4, 60; and C.I. Pigment Green 7.

Moreover, among the magenta colorants, examples of magenta-colored dyeinclude C.I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63,81, 82, 83, 84, 100, 109, 111, 121, 122; C.I. Disperse Red 9; C.I.Solvent Violet 8, 13, 14, 21, 27; C.I. Disperse Violet 1; C.I. Basic Red1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37,38, 39, 40; C.I. Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27 and28.

Among the magenta-colored colorants, examples of magenta-colored pigmentinclude C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 42,48:1, 48:2, 48:3, 48:4, 49, 49:1, 50, 51, 52, 52:2, 53:1, 54, 55, 56,57:1, 58, 60, 60:1, 63, 63:1, 63:2, 64, 64:1, 67, 68, 81, 83, 87, 88,89, 90, 92, 101, 104, 105, 106, 108, 112, 114, 122, 123, 139, 144, 146,147, 149, 150, 151, 163, 166, 168, 170, 171, 172, 175, 176, 177, 178,179, 184, 185, 187, 190, 193, 202, 206, 207, 209, 219, 222, 224, 238,245; C.I. Pigment Violet 3, 9, 19, 23, 31, 32, 33, 36, 38, 43, 50; C.I.Vat Red 1, 2, 10, 13, 15, 23, 29 and 35.

Moreover, examples of the yellow-colored colorants includeyellow-colored dyes such as C.I. Solvent Yellow 19, 44, 77, 79, 81, 82,93, 98, 103, 104, 112, and 162; yellow-colored pigments such as C.I.Pigment Orange 31, 43; C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11,12, 13, 14, 15, 16, 17, 23, 24, 34, 35, 37, 42, 53, 55, 65, 73, 74, 75,81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 108, 109, 110, 113, 114, 116,117, 120, 128, 129, 133, 138, 139, 147, 150, 151, 153, 154, 155, 156,167, 172, 173, 180, 185, 195; C.I. Vat Yellow 1, 3, and 20.

Various colorants such as cyan-colored colorants, magenta-coloredcolorants, and yellow-colorant colorants may be employed singly or in acombination of two or more kinds, respectively. In this regard, in thecase where two or more kinds of various colorants such as cyan-coloredcolorants, magenta-colored colorants, and yellow-colorant colorants areused, the mixing ratio (or blending ratio) of these colorants is notparticularly restricted and can be suitably selected according to thekind of each colorant, an objective color, and the like.

In the case where the film for semiconductor back surface 2 is colored,the colored form is not particularly restricted. The film forsemiconductor back surface may be, for example, a single-layerfilm-shaped article added with a coloring agent. Moreover, the film maybe a laminated film where a resin layer formed of at least athermosetting resin and a coloring agent layer are at least laminated.In this regard, in the case where the film for semiconductor backsurface 2 is a laminated film of the resin layer and the coloring agentlayer, the film for semiconductor back surface 2 in the laminated formpreferably has a laminated form of a resin layer/a coloring agentlayer/a resin layer. In this case, two resin layers at both sides of thecoloring agent layer may be resin layers having the same composition ormay be resin layers having different composition.

Into the film for semiconductor back surface 2, other additives can besuitably blended according to the necessity. Examples of the otheradditives include an extender, an antiaging agent, an antioxidant, and asurfactant, in addition to a filler, a flame retardant, asilane-coupling agent, and an ion-trapping agent.

The filler may be any of an inorganic filler and an organic filler butan inorganic filler is suitable. By blending a filler such as aninorganic filler, imparting of electric conductivity to the film forsemiconductor back surface, improvement of the thermal conductivity,control of elastic modulus, and the like can be achieved. In thisregard, the film for semiconductor back surface 2 may be electricallyconductive or non-conductive. Examples of the inorganic filler includevarious inorganic powders composed of silica, clay, gypsum, calciumcarbonate, barium sulfate, alumina oxide, beryllium oxide, ceramics suchas silicone carbide and silicone nitride, metals or alloys such asaluminum, copper, silver, gold, nickel, chromium, lead, tin, zinc,palladium, and solder, carbon, and the like. The filler may be employedsingly or in a combination of two or more kinds. Particularly, thefiller is suitably silica and more suitably fused silica. The averageparticle diameter of the inorganic filler is preferably within the rangeof 0.1 μm to 80 μm. The average particle diameter of the inorganicfiller can be measured by a laser diffraction-type particle sizedistribution measurement apparatus.

The blending amount of the filler (in particular, inorganic filler) ispreferably 80 parts by weight or less (0 part by weight to 80 parts byweight) and more preferably 0 part by weight to 70 parts by weight basedon 100 parts by weight of the organic resin components.

Examples of the flame retardant include antimony trioxide, antimonypentoxide, and brominated epoxy resins. The flame retardant may beemployed singly or in a combination of two or more kinds. Examples ofthe silane coupling agent includeβ-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,γ-glycidoxypropyltrimethoxysilane, andγ-glycidoxypropylmethyldiethoxysilane. The silane coupling agent may beemployed singly or in a combination of two or more kinds. Examples ofthe ion-trapping agent include hydrotalcites and bismuth hydroxide. Theion-trapping agent may be employed singly or in a combination of two ormore kinds.

The film for semiconductor back surface 2 can be, for example, formed byutilizing a commonly used method including mixing a thermosetting resinsuch as an epoxy resin and, if necessary, a thermoplastic resin such asan acrylic resin and optional solvent and other additives to prepare aresin composition, followed by forming it to a film-shaped layer.Specifically, a film-shaped layer (adhesive layer) as the film forsemiconductor back surface can be formed, for example, by a methodincluding applying the resin composition on the pressure-sensitiveadhesive layer 32 of the dicing tape; a method including applying theresin composition on an appropriate separator (such as release paper) toform a resin layer (or an adhesive layer) and then transferring(transcribing) it on the pressure-sensitive adhesive layer 32; or thelike. In this regard, the resin composition may be a solution or adispersion.

Incidentally, in the case where the film for semiconductor back surface2 is formed of a resin composition containing a thermosetting resin suchas an epoxy resin, the film for semiconductor back surface is in a statethat the thermosetting resin is uncured or partially cured at a stagebefore the film is applied to a semiconductor wafer. In this case, afterit is applied to the semiconductor wafer (specifically, usually, at thetime when the encapsulating material is cured in the flip chip bondingstep), the thermosetting resin in the film for semiconductor backsurface is completely or almost completely cured.

As above, since the film for semiconductor back surface is in a statethat the thermosetting resin is uncured or partially cured even when thefilm contains the thermosetting resin, the gel fraction of the film forsemiconductor back surface is not particularly restricted but is, forexample, suitably selected from the range of 50% by weight or less (0 to50% by weight) and is preferably 30% by weight or less (0 to 30% byweight) and particularly preferably 10% by weight or less (0 to 10% byweight). The gel fraction of the film for semiconductor back surface canbe measured by the following measuring method.

<Gel Fraction Measuring Method>

About 0.1 g of a sample is sampled from the film for semiconductor backsurface 2 and precisely weighed (weight of sample) and, after the sampleis wrapped in a mesh-type sheet, it is immersed in about 50 mL oftoluene at room temperature for 1 week. Thereafter, a solvent-insolublematter (content in the mesh-type sheet) is taken out of the toluene anddried at 130° C. for about 2 hours, the solvent-insoluble matter afterdrying is weighed (weight after immersion and drying), and a gelfraction (% by weight) is then calculated according to the followingexpression (a).

Gel fraction (% by weight)=[(Weight after immersion and Drying)/(Weightof sample)]×100  (a)

The gel fraction of the film for semiconductor back surface can becontrolled by the kind and content of the resin components and the kindand content of the crosslinking agent and besides, heating temperature,heating time and the like.

In the invention, in the case where the film for semiconductor backsurface is a film-shaped article formed of a resin compositioncontaining a thermosetting resin such as an epoxy resin, closeadhesiveness to a semiconductor wafer can be effectively exhibited.

Incidentally, since cutting water is used in the dicing step of thesemiconductor wafer, the film for semiconductor back surface absorbsmoisture to have a moisture content of a normal state or more in somecases. When flip chip bonding is performed with still maintaining such ahigh moisture content, water vapor remains at the adhesion interfacebetween the film for semiconductor back surface and the semiconductorwafer or its processed body (semiconductor) and lifting is generated insome cases. Therefore, by constituting the film for semiconductor backsurface as a configuration in which a core material having a highmoisture permeability is provided on each surface thereof, water vapordiffuses and thus it becomes possible to avoid such a problem. From sucha viewpoint, a multilayered structure in which the film forsemiconductor back surface is formed at one surface or both surfaces ofthe core material may be used as the film for semiconductor backsurface. Examples of the core material include films (e.g., polyimidefilms, polyester films, polyethylene terephthalate films, polyethylenenaphthalate films, polycarbonate films, etc.), resin substratesreinforced with a glass fiber or a plastic nonwoven fiber, siliconsubstrates, and glass substrates.

The thickness (total thickness in the case of the laminated film) of thefilm for semiconductor back surface 2 is not particularly restricted butcan be, for example, suitably selected from the range of about 2 μm to200 μm. Furthermore, the thickness is preferably about 4 μm to 160 μm,more preferably about 6 μm to 100 μm, and particularly about 10 μm to 80μm.

The tensile storage elastic modulus of the film for semiconductor backsurface 2 in an uncured state at 23° C. is preferably 1 GPa or more(e.g., 1 GPa to 50 GPa), more preferably 2 GPa or more, andparticularly, 3 GPa or more is suitable. When the tensile storageelastic modulus is 1 GPa or more, the attachment of the film forsemiconductor back surface to a support can be effectively suppressed orprevented at the time when the film for semiconductor back surface 2 isplaced on the support and transportation and the like are performedafter the semiconductor chip is peeled from the pressure-sensitiveadhesive layer 32 of the dicing tape together with the film forsemiconductor back surface 2. In this regard, the support is, forexample, a top tape, a bottom tape, and the like in a carrier tape. Inthe case where the film for semiconductor back surface 2 is formed of aresin composition containing a thermosetting resin, as mentioned above,the thermosetting resin is usually in a uncured or partially curedstate, so that the tensile storage elastic modulus of the film forsemiconductor back surface at 23° C. is a tensile storage elasticmodulus at 23° C. in a state that the thermosetting resin is uncured orpartially cured.

Here, the film for semiconductor back surface 2 may be either a singlelayer or a laminated film where a plurality of layers are laminated. Inthe case of the laminated film, the tensile storage elastic modulus issufficiently 1 GPa or more (e.g., 1 GPa to 50 GPa) as the wholelaminated film in an uncured state. Also the tensile storage elasticmodulus (23° C.) of the film for semiconductor back surface in anuncured state can be controlled by suitably setting up the kind andcontent of the resin components (thermoplastic resin and/orthermosetting resin) or the kind and content of a filler such as asilica filler. In the case where the film for semiconductor back surface2 is a laminated film where a plurality of layers are laminated (in thecase where the film for semiconductor back surface has a form of thelaminated layer), as the laminated layer form, for example, a laminatedform composed of a wafer adhesive layer and a laser marking layer can beexemplified. Moreover, between the wafer adhesive layer and the lasermarking layer, other layers (an intermediate layer, a light-shieldinglayer, a reinforcing layer, a colored layer, a base material layer, anelectromagnetic wave-shielding layer, a heat conductive layer, apressure-sensitive adhesive layer, etc.) may be provided. In thisregard, the wafer adhesive layer is a layer which exhibits an excellentclose adhesiveness (adhesive property) to a wafer and a layer whichcomes into contact with the back surface of a wafer. On the other hand,the laser marking layer is a layer which exhibits an excellent lasermarking property and a layer which is utilized at the laser marking onthe back surface of a semiconductor chip.

The tensile storage elastic modulus is determined by preparing the filmfor semiconductor back surface 2 in an uncured state without laminationonto the dicing tape 3 and measuring elastic modulus in a tensile modeunder conditions of a sample width of 10 mm, a sample length of 22.5 mm,a sample thickness of 0.2 mm, a frequency of 1 Hz, and a temperatureelevating rate of 10° C./minute under a nitrogen atmosphere at aprescribed temperature (23° C.) using a dynamic viscoelasticitymeasuring apparatus “Solid Analyzer RS A2” manufactured by RheometricsCo. Ltd. and the measured elastic modulus is regarded as a value oftensile storage elastic modulus obtained.

Preferably, the film for semiconductor back surface 2 is protected witha separator (release liner) on at least one surface thereof (not shownin figures). For example, in the dicing tape-integrated film forsemiconductor back surface 1, a separator may be provided on at leastone surface of the film for semiconductor back surface. On the otherhand, in the film for semiconductor back surface not integrated with adicing tape, a separator may be provided on one surface or both surfacesof the film for semiconductor back surface. The separator has a functionas a protective material for protecting the film for semiconductor backsurface until it is practically used. Further, in the dicingtape-integrated film for semiconductor back surface 1, the separator mayfurther serve as the supporting base material in transferring the filmfor semiconductor back surface 2 onto the pressure-sensitive adhesivelayer 32 of the base material of the dicing tape. The separator ispeeled off when a semiconductor wafer is attached onto the film forsemiconductor back surface. As the separator, a film of polyethylene orpolypropylene, as well as a plastic film (such as polyethyleneterephthalate), a paper or the like whose surface is coated with areleasing agent such as a fluorine-based releasing agent or a long-chainalkyl acrylate-based releasing agent can also be used. The separator canbe formed by a conventionally known method. Moreover, the thickness orthe like of the separator is not particularly restricted.

In case where the film for semiconductor back surface 2 is not laminatedwith the dicing tape 3, the film for semiconductor back surface 2 may bewound up along with one separator having a release layer on both sidesthereof, into a roll in which the film 2 is protected with the separatorhaving a release layer on both surfaces thereof; or the film 2 may beprotected with a separator having a release layer on at least onesurface thereof.

Moreover, the light transmittance with a visible light (visible lighttransmittance, wavelength: 400 to 800 nm) in the film for semiconductorback surface 2 is not particularly restricted but is, for example,preferably in the range of 20% or less (0 to 20%), more preferably 10%or less (0 to 10%), and particularly preferably 5% or less (0 to 5%).When the film for semiconductor back surface 2 has a visible lighttransmittance of more than 20%, there is a concern that the transmissionof the light may adversely influence the semiconductor element. Thevisible light transmittance (%) can be controlled by the kind andcontent of the resin components of the film for semiconductor backsurface 2, the kind and content of the coloring agent (such as pigmentor dye), the content of the inorganic filer, and the like.

The visible light transmittance (%) of the film for semiconductor backsurface 2 can be determined as follows. Namely, a film for semiconductorback surface 2 having a thickness (average thickness) of 20 μm itself isprepared. Then, the film for semiconductor back surface 2 is irradiatedwith a visible light having a wavelength of 400 to 800 nm in aprescribed intensity [apparatus: a visible light generating apparatusmanufactured by Shimadzu Corporation [trade name “ABSORPTION SPECTROPHOTOMETER”], and the intensity of transmitted visible light ismeasured. Further, the visible light transmittance (%) can be determinedbased on intensity change before and after the transmittance of thevisible light through the film for semiconductor back surface 2. In thisregard, it is also possible to derive visible light transmittance (%;wavelength: 400 to 800 nm) of the film for semiconductor back surface 2having a thickness of 20 μm from the value of the visible lighttransmittance (%; wavelength: 400 to 800 nm) of the film forsemiconductor back surface 2 whose thickness is not 20 μm. In theinvention, the visible light transmittance (%) is determined in the caseof the film for semiconductor back surface 2 having a thickness of 20μm, but the film for semiconductor back surface according to theinvention is not limited to one having a thickness of 20 μm.

Moreover, as the film for semiconductor back surface 2, one having lowermoisture absorbance is more preferred. Specifically, the moistureabsorbance is preferably 1% by weight or less and more preferably 0.8%by weight or less. By regulating the moisture absorbance to 1% by weightor less, the laser marking property can be enhanced. Moreover, forexample, the generation of voids between the film for semiconductor backsurface 2 and the semiconductor element can be suppressed or preventedin the reflow step. The moisture absorbance is a value calculated from aweight change before and after the film for semiconductor back surface 2is allowed to stand under an atmosphere of a temperature of 85° C. and ahumidity of 85% RH for 168 hours. In the case where the film forsemiconductor back surface 2 is formed of a resin composition containinga thermosetting resin, the moisture absorbance means a value obtainedwhen the film after thermal curing is allowed to stand under anatmosphere of a temperature of 85° C. and a humidity of 85% RH for 168hours. Moreover, the moisture absorbance can be regulated, for example,by changing the amount of the inorganic filler to be added.

Moreover, as the film for semiconductor back surface 2, one having asmaller ratio of volatile matter is more preferred. Specifically, theratio of weight decrease (weight decrease ratio) of the film forsemiconductor back surface 2 after heating treatment is preferably 1% byweight or less and more preferably 0.8% by weight or less. Theconditions for the heating treatment are a heating temperature of 250°C. and a heating time of 1 hour. By regulating the weight decrease ratioto 1% by weight or less, the laser marking property can be enhanced.Moreover, for example, the generation of cracks in a flip chip typesemiconductor device can be suppressed or prevented in the reflow step.The weight decrease ratio can be regulated, for example, by adding aninorganic substance capable of reducing the crack generation atlead-free solder reflow. In the case where the film for semiconductorback surface 2 is formed of a resin composition containing athermosetting resin component, the weight decrease ratio is a valueobtained when the film for semiconductor back surface after thermalcuring is heated under conditions of a temperature of 250° C. and aheating time of 1 hour.

(Dicing Tape)

The dicing tape 3 includes a base material 31 and a pressure-sensitiveadhesive layer 32 formed on the base material 31. Thus, it is sufficientthat the dicing tape 3 has a configuration in which the base material 31and the pressure-sensitive adhesive layer 32 are laminated.

(Base Material)

The base material (supporting base material) can be used as a supportingmaterial for the pressure-sensitive adhesive layer and the like. Thebase material 31 preferably has a radiation ray-transmitting property.As the base material 31, for example, suitable thin materials, e.g.,paper-based base materials such as paper; fiber-based base materialssuch as fabrics, non-woven fabrics, felts, and nets; metal-based basematerials such as metal foils and metal plates; plastic base materialssuch as plastic films and sheets; rubber-based base materials such asrubber sheets; foamed bodies such as foamed sheets; and laminatesthereof [particularly, laminates of plastic based materials with otherbase materials, laminates of plastic films (or sheets) each other, etc.]can be used. In the invention, as the base material, plastic basematerials such as plastic films and sheets can be suitably employed.Examples of raw materials for such plastic materials include olefinicresins such as polyethylene (PE), polypropylene (PP), andethylene-propylene copolymers; copolymers using ethylene as a monomercomponent, such as ethylene-vinyl acetate copolymers (EVA), ionomerresins, ethylene-(meth)acrylic acid copolymers, andethylene-(meth)acrylic acid ester (random, alternating) copolymers;polyesters such as polyethylene terephthalate (PET), polyethylenenaphthalate (PEN), and polybutylene terephthalate (PBT); acrylic resins;polyvinyl chloride (PVC); polyurethanes; polycarbonates; polyphenylenesulfide (PPS); amide-based resins such as polyamides (Nylon) and wholearomatic polyamides (aramide); polyether ether ketones (PEEK);polyimides; polyetherimides; polyvinylidene chloride; ABS(acrylonitrile-butadiene-styrene copolymers); cellulose-based resins;silicone resins; and fluorinated resins.

In addition, the materials for the base material 31 include polymerssuch as crosslinked materials of the foregoing resins. The plastic filmsmay be used without stretching or may be used after subjected to auniaxial or biaxial stretching treatment, if necessary. According to theresin sheet to which thermal contraction property is imparted by astretching treatment or the like, the adhered area between thepressure-sensitive adhesive layer 32 and the film for semiconductor backsurface 2 is reduced by thermal contraction of the base material 31after dicing and thus the recovery of the semiconductor chip can befacilitated.

A commonly used surface treatment, e.g., a chemical or physicaltreatment such as a chromate treatment, ozone exposure, flame exposure,exposure to high-voltage electric shock, or an ionized radiationtreatment, or a coating treatment with an undercoating agent e.g., apressure-sensitive adhesive substance to be mentioned later) may beapplied onto the surface of the base material 31 in order to enhanceclose adhesiveness with the adjacent layer, holding properties, and thelike.

As the base material 31, the same kind or different kinds of materialscan be suitably selected and used and, if necessary, several kinds ofmaterials can be blended and used. Moreover, to the base material 31,for imparting antistatic ability, a vapor deposition layer of aconductive substance having a thickness of about 30 to 500 angstrom,which is composed of a metal, alloy or an oxide thereof, can be formedon the base material 31. The base material 31 may be a single layer or amultilayer of two or more thereof.

The thickness (total thickness in the case of the laminated layer) ofthe base material 31 is not particularly restricted and can beappropriately selected depending on strength, flexibility, intendedpurpose of use, and the like. For example, the thickness is generally1,000 μm or less (e.g., 1 μm to 1,000 μm), preferably 10 μm to 500 μm,further preferably 20 μm to 300 μm, and particularly preferably about 30μm to 200 μm but is not limited thereto.

Incidentally, the base material 31 may contain various additives (acoloring agent, a filler, a plasticizer, an antiaging agent, anantioxidant, a surfactant, a flame retardant, etc.) within the rangewhere the advantages and the like of the invention are not impaired.

(Pressure-Sensitive Adhesive Layer)

The pressure-sensitive adhesive layer 32 is formed of apressure-sensitive adhesive and has a pressure-sensitive adhesiveness.Not specifically defined, the pressure-sensitive adhesive may besuitably selected from known pressure-sensitive adhesives. Concretely,as the pressure-sensitive adhesive, for example, those having theabove-mentioned characteristics are suitably selected from knownpressure-sensitive adhesives such as acrylic pressure-sensitiveadhesives, rubber-based pressure-sensitive adhesives, vinyl alkylether-based pressure-sensitive adhesives, silicone-basedpressure-sensitive adhesives, polyester-based pressure-sensitiveadhesives, polyamide-based pressure-sensitive adhesives, urethane-basedpressure-sensitive adhesives, fluorine-based pressure-sensitiveadhesives, styrene-diene block copolymer-based pressure-sensitiveadhesives, and creep characteristics-improved pressure-sensitiveadhesives prepared by incorporating a thermofusible resin having amelting point of not higher than 200° C. to the above-mentionedpressure-sensitive adhesive (for example, see JP-A 56-61468,JP-A-61-174857, JP-A-63-17981, JP-A-56-13040, herein incorporated byreference), and are used herein. As the pressure-sensitive adhesive,also usable here are radiation-curable pressure-sensitive adhesives (orenergy ray-curable pressure-sensitive adhesives) and thermallyexpandable pressure-sensitive adhesives. One or more suchpressure-sensitive adhesives may be used here either singly or ascombined.

As the pressure-sensitive adhesive, preferred for use herein are acrylicpressure-sensitive adhesives and rubber-based pressure-sensitiveadhesives, and more preferred are acrylic pressure-sensitive adhesives.The acrylic pressure-sensitive adhesives include those comprising, asthe base polymer, an acrylic polymer (homopolymer or copolymer) of oneor more alkyl (meth)acrylates as monomer component(s).

The alkyl (meth)acrylate for the acrylic pressure-sensitive adhesiveincludes, for example, methyl (meth)acrylate, ethyl (meth)acrylate,propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate,isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate,pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate,octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl(meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl(meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl(meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate,pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl(meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate,eicosyl (meth)acrylate, etc. As the alkyl (meth)acrylate, preferred arethose in which the alkyl group has from 4 to 18 carbon atoms. In thealkyl (meth)acrylate, the alkyl group may be linear or branched.

The acrylic polymer may contain, if desired, a unit corresponding to anyother monomer component copolymerizable with the above-mentioned alkyl(meth)acrylate (copolymerizable monomer component), for the purpose ofimproving the cohesive force, the heat resistance and thecrosslinkability thereof. The copolymerizable monomer componentincludes, for example, carboxyl group-containing monomers such as(meth)acrylic acid (acrylic acid, methacrylic acid), carboxyethylacrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaricacid, crotonic acid; acid anhydride group-containing monomers such asmaleic anhydride, itaconic anhydride; hydroxyl group-containing monomerssuch as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate,hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, hydroxyoctyl(meth)acrylate, hydroxydecyl (meth)acrylate, hydroxylauryl(meth)acrylate, (4-hydroxymethylcyclohexyl)methyl methacrylate; sulfonicacid group-containing monomers such as styrenesulfonic acid,allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid,(meth)acrylamide-propanesulfonic acid, sulfopropyl (meth)acrylate,(meth)acryloyloxynaphthalenesulfonic acid; phosphoric acidgroup-containing monomers such as 2-hydroxyethyl acryloylphosphate;(N-substituted) amide monomers such as (meth)acrylamide,N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide,N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide;aminoalkyl (meth)acrylate monomers such as aminoethyl (meth)acrylate,N,N-dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate;alkoxyalkyl (meth)acrylate monomers such as methoxyethyl (meth)acrylate,ethoxyethyl (meth)acrylate; cyanoacrylate monomers such asacrylonitrile, methacrylonitrile; epoxy group-containing acrylicmonomers such as glycidyl (meth)acrylate; styrene monomers such asstyrene, α-methylstyrene; vinyl ester monomers such as vinyl acetate,vinyl propionate; olefin monomers such as isoprene, butadiene,isobutylene; vinyl ether monomers such as vinyl ether;nitrogen-containing monomers such as N-vinylpyrrolidone,methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine,vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole,vinyloxazole, vinylmorpholine, N-vinylcarbonamides, N-vinylcaprolactam;maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide,N-laurylmaleimide, N-phenylmaleimide; itaconimide monomers such asN-methylitaconimide, N-ethylitaconimide, N-butylitaconimide,N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide,N-laurylitaconimide; succinimide monomers such asN-(meth)acryloyloxymethylenesuccinimide,N-(meth)acryloyl-6-oxyhexamethylenesuccinimide,N-(meth)acryloyl-8-oxyoctamethylenesuccinimide; acryl glycolate monomerssuch as polyethylene glycol (meth)acrylate, polypropylene glycol(meth)acrylate, methoxyethylene glycol (meth)acrylate,methoxypolypropylene glycol (meth)acrylate; acrylate monomers having ahetero ring, a halogen atom, a silicone atom or the like such astetrahydrofurfuryl (meth)acrylate, fluoro(meth)acrylate, silicone(meth)acrylate; polyfunctional monomers such as hexanedioldi(meth)acrylate, (poly)ethylene glycol di(meth)acrylate,(poly)propylene glycol di(meth)acrylate, neopentylglycoldi(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropanetri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritolhexa(meth)acrylate, epoxyacrylate, polyester acrylate, urethaneacrylate, divinylbenzene, butyl di(meth)acrylate, hexyldi(meth)acrylate, etc. One or more these copolymerizable monomercomponents may be used here either singly or as combined.

The radiation-curable pressure-sensitive adhesive (or energy ray-curablepressure-sensitive adhesive) (composition) usable in the inventionincludes, for example, an internal-type radiation-curablepressure-sensitive adhesive comprising, as the base polymer, a polymerhaving a radical-reactive carbon-carbon double bond in the polymer sidechain, main chain or main chain terminal, and a radiation-curablepressure-sensitive adhesive prepared by incorporating a UV-curablemonomer component or oligomer component in a pressure-sensitiveadhesive. The thermally expandable pressure-sensitive adhesive alsousable here includes, for example, those comprising a pressure-sensitiveadhesive and a foaming agent (especially thermally expandablemicrospheres).

In the invention, the pressure-sensitive adhesive layer 32 may containvarious additives (e.g., a tackifying resin, a coloring agent, athickener, an extender, a filler, a plasticizer, an antiaging agent, anantioxidant, a surfactant, a crosslinking agent, etc.) within the rangewhere the advantages of the invention are not impaired.

The crosslinking agent is not particularly restricted and knowncrosslinking agents can be used. Specifically, as the crosslinkingagent, not only isocyanate-based crosslinking agents, epoxy-basedcrosslinking agents, melamine-based crosslinking agents, andperoxide-based crosslinking agents but also urea-based crosslinkingagents, metal alkoxide-based crosslinking agents, metal chelate-basedcrosslinking agents, metal salt-based crosslinking agents,carbodiimide-based crosslinking agents, oxazoline-based crosslinkingagents, aziridine-based crosslinking agents, amine-based crosslinkingagents, and the like may be mentioned, and isocyanate-based crosslinkingagents and epoxy-based crosslinking agents are suitable. Thecrosslinking agent may be employed singly or in a combination of two ormore kinds. Incidentally, the amount of the crosslinking agent to beused is not particularly restricted.

Examples of the isocyanate-based crosslinking agents include loweraliphatic polyisocyanates such as 1,2-ethylene diisocyanate,1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; alicyclicpolyisocyanates such as cyclopentylene diisocyanate, cyclohexylenediisocyanate, isophorone diisocyanate, hydrogenated tolylenediisocyanate, and hydrogenated xylylene diisocyanate; and aromaticpolyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylenediisocyanate, 4,4′-diphenylmethane diisocyanate, and xylylenediisocyanate. In addition, a trimethylolpropane/tolylene diisocyanatetrimer adduct [a trade name “COLONATE L” manufactured by NipponPolyurethane Industry Co., Ltd.], a trimethylolpropane/hexamethylenediisocyanate trimer adduct [a trade name “COLONATE HL” manufactured byNippon Polyurethane Industry Co., Ltd.], and the like are also used.Moreover, examples of the epoxy-based crosslinking agents includeN,N,N′,N′-tetraglycidyl-m-xylenediamine, diglycidylaniline,1,3-bis(N,N-glycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidylether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidylether, propylene glycol diglycidyl ether, polyethylene glycol diglycidylether, polypropylene glycol diglycidyl ether, sorbitol polyglycidylether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether,polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether,trimethylolpropnane polyglycidyl ether, adipic acid diglycidyl ester,o-phthalic acid diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, resorcin diglycidyl ether, and bisphenol-S-diglycidylether, and also epoxy-based resins having two or more epoxy groups inthe molecule.

In place of using the crosslinking agent or along with the crosslinkingagent in the invention, the pressure-sensitive adhesive layer may becrosslinked through irradiation with electron rays or UV rays.

The pressure-sensitive adhesive layer 32 can be, for example, formed byutilizing a commonly used method including mixing a pressure-sensitiveadhesive and optional solvent and other additives and then shaping themixture into a sheet-like layer. Specifically, for example, there may bementioned a method including applying a mixture containing apressure-sensitive adhesive and optional solvent and other additives onthe base material 31; a method including applying the foregoing mixtureon an appropriate separator (such as a release paper) to form apressure-sensitive adhesive layer 32 and then transferring(transcribing) it on the base material 31; or the like.

The adhesive force of the pressure-sensitive adhesive layer 32 of thedicing tape 3 to the film for flip chip type semiconductor back surface2 (23° C., peeling angle of 180 degrees, peeling rate of 300 mm/min) ispreferably within a range of from 0.02 N/20 mm to 10 N/20 mm, morepreferably from 0.05 N/20 mm to 5 N/20 mm. When the adhesive force is atleast 0.02 N/20 mm, then the semiconductor chips may be prevented fromflying away in dicing semiconductor wafer. On the other hand, when theadhesive force is at most 10 N/20 mm, then it facilitates peeling ofsemiconductor chips in picking up them, and prevents thepressure-sensitive adhesive from remaining

Incidentally, in the invention, the film for flip-chip typesemiconductor back surface 2 or the dicing tape-integrated film forsemiconductor back surface 1 can be made to have an antistatic function.Owing to this configuration, the circuit can be prevented from breakingdown due to the generation of electrostatic energy at the time adhesionand at the time of peeling thereof or due to charging of a semiconductorwafer or the like by the electrostatic energy. Imparting of theantistatic function can be performed by an appropriate manner such as amethod of adding an antistatic agent or a conductive substance to thebase material 31, the pressure-sensitive adhesive layer 32, and the filmfor semiconductor back surface 2, or a method of providing a conductivelayer composed of a charge-transfer complex, a metal film, or the likeonto the base material 31. As these methods, a method in which animpurity ion having a fear of changing quality of the semiconductorwafer is difficult to generate is preferable. Examples of the conductivesubstance (conductive filler) to be blended for the purpose of impartingconductivity, improving thermal conductivity, and the like include asphere-shaped, a needle-shaped, or a flake-shaped metal powder ofsilver, aluminum, gold, copper, nickel, a conductive alloy, or the like;a metal oxide such as alumina; amorphous carbon black, and graphite.However, the film for semiconductor back surface 2 is preferablynon-conductive from the viewpoint of having no electric leakage.

Moreover, the film for flip-chip type semiconductor back surface 2 orthe dicing tape-integrated film for semiconductor back surface 1 may beformed in a form where it is wound as a roll or may be formed in a formwhere the sheet (film) is laminated. For example, in the case where thefilm has the form where it is wound as a roll, the film is wound as aroll in a state that the film for semiconductor back surface 2 or thelaminate of the film for semiconductor back surface 2 and the dicingtape 3 is protected by a separator according to needs, whereby the filmcan be prepared as a film for semiconductor back surface 2 or a dicingtape-integrated film for semiconductor back surface 1 in a state or formwhere it is wound as a roll. In this regard, the dicing tape-integratedfilm for semiconductor back surface 1 in the state or form where it iswound as a roll may be constituted by the base material 31, thepressure-sensitive adhesive layer 32 formed on one surface of the basematerial 31, the film for semiconductor back surface 2 formed on thepressure-sensitive adhesive layer 32, and a releasably treated layer(rear surface treated layer) formed on the other surface of the basematerial 31.

Incidentally, the thickness of the dicing tape-integrated film forsemiconductor back surface 1 (total thickness of the thickness of thefilm for semiconductor back surface and the thickness of the dicing tapeincluding the base material 31 and the pressure-sensitive adhesive layer32) can be, for example, selected from the range of 25 μm to 1,600 μm,and it is preferably from 30 μm to 850 μm, more preferably 35 μm to 500μm, and particularly preferably 50 μm to 330 μm.

In this regard, in the dicing tape-integrated film for semiconductorback surface 1, by controlling the ratio of the thickness of the filmfor semiconductor back surface 2 to the thickness of thepressure-sensitive adhesive layer 32 of the dicing tape 3 or the ratioof the thickness of the film for semiconductor back surface 2 to thethickness of the dicing tape (total thickness of the base material 31and the pressure-sensitive adhesive layer 32), a dicing property at thedicing step, a picking-up property at the picking-up step, and the likecan be improved and the dicing tape-integrated film for semiconductorback surface 1 can be effectively utilized from the dicing step of thesemiconductor wafer to the flip chip bonding step of the semiconductorchip.

(Producing Method of Dicing Tape-Integrated Film for Semiconductor BackSurface)

The producing method of the dicing tape-integrated film forsemiconductor back surface according to the present embodiment isdescribed while using the dicing tape-integrated film for semiconductorback surface 1 shown in FIG. 1 as an example. First, the base material31 can be formed by a conventionally known film-forming method. Examplesof the film-forming method include a calendar film-forming method, acasting method in an organic solvent, an inflation extrusion method in aclosely sealed system, a T-die extrusion method, a co-extrusion method,and a dry laminating method.

Next, the pressure-sensitive adhesive composition is applied to the basematerial 31 and dried thereon (and optionally crosslinked under heat) toform the pressure-sensitive adhesive layer 32. The coating systemincludes roll coating, screen coating, gravure coating, etc. Thepressure-sensitive adhesive layer composition may be directly applied tothe base material 31 to form the pressure-sensitive adhesive layer 32 onthe base material 31; or the pressure-sensitive adhesive composition maybe applied to a release sheet or the like of which the surface has beenprocessed for lubrication, to form the pressure-sensitive adhesive layer32 thereon, and the pressure-sensitive adhesive layer 32 may betransferred onto the base material 31. With that, the dicing tape 3 isformed having the pressure-sensitive adhesive layer 32 formed on thebase material 31.

On the other hand, a forming material for forming the film forsemiconductor back surface 2 is applied onto a release sheet to form acoating layer having a predetermined thickness after dried, and thendried under a predetermined condition (optionally heated in case wherethermal curing is necessary, and dried) to form the coating layer. Thecoating layer is transferred onto the pressure-sensitive adhesive layer32 to thereby form the film for semiconductor back surface 2 on thepressure-sensitive adhesive layer 32. The film for semiconductor backsurface 2 may also be formed on the pressure-sensitive adhesive layer 32by directly applying the forming material for forming the film forsemiconductor back surface 2 onto the pressure-sensitive adhesive layer32 and then drying it under a predetermined condition (optionallyheating it in case where thermal curing is necessary, and drying it).According to the process as above, the dicing tape-integrated film forsemiconductor back surface 1 of the invention can be obtained. In casewhere thermal curing is needed in forming the film for semiconductorback surface 2, it is important that the thermal curing is effected tosuch a degree that the coating layer could be partially cured, butpreferably, the coating layer is not thermally cured.

The dicing tape-integrated film for semiconductor back surface 1 of theinvention can be suitably used at the production of a semiconductordevice including the flip chip connection step. Namely, the dicingtape-integrated film for semiconductor back surface 1 of the inventionis used at the production of a flip chip-mounted semiconductor deviceand thus the flip chip-mounted semiconductor device is produced in acondition or form where the film for semiconductor back surface 2 of thedicing tape-integrated film for semiconductor back surface 1 is attachedto the back surface of the semiconductor chip. Therefore, the dicingtape-integrated film for semiconductor back surface 1 of the inventioncan be used for a flip chip-mounted semiconductor device (asemiconductor device in a state or form where the semiconductor chip isfixed to an adherend such as a substrate by a flip chip bonding method).

The film for semiconductor back surface 2 is usable also for flipchip-mounted semiconductor devices (semiconductor devices in a state orform where a semiconductor chip is fixed to the adherend such as asubstrate or the like in a flip chip bonding method), like in the dicingtape-integrated film for semiconductor back surface 1.

(Semiconductor Wafer)

The semiconductor wafer is not particularly restricted as long as it isa known or commonly used semiconductor wafer and can be appropriatelyselected and used among semiconductor wafers made of various materials.In the invention, as the semiconductor wafer, a silicon wafer can besuitable used.

(Production Process of Semiconductor Device)

The process for producing a semiconductor device according to theinvention will be described referring to FIGS. 2A to 2D. FIGS. 2A to 2Dare cross-sectional schematic views showing a process for producing asemiconductor device in the case where a dicing tape-integrated film forsemiconductor back surface 1 is used.

In the semiconductor device producing process, the dicingtape-integrated film for semiconductor back surface 1 is used to producea semiconductor device. Concretely, the production process comprises atleast a step of attaching a semiconductor wafer onto the film forsemiconductor back surface in the dicing tape-integrated film forsemiconductor back surface, a step of dicing the semiconductor wafer toform a semiconductor element in which the cutting depth is so controlledas to fall within a range overstepping on one side of thepressure-sensitive adhesive layer that faces the film for semiconductorback surface and not reaching the other side thereof that faces the basematerial, a peeling step of peeling the semiconductor chip from thepressure-sensitive adhesive layer of the dicing tape together with thefilm for semiconductor back surface, and a step of flip chip-connectingthe semiconductor chip onto an adherend.

(Mounting Step)

First, as shown in FIG. 2A, a separator optionally provided on the filmfor semiconductor back surface 2 of the dicing tape-integrated film forsemiconductor back surface 1 is suitably peeled off and thesemiconductor wafer 4 is attached onto the film for semiconductor backsurface 2 to be fixed by adhesion and holding (mounting step). On thisoccasion, the film for semiconductor back surface 2 is in an uncuredstate (including a semi-cured state). Moreover, the dicingtape-integrated film for semiconductor back surface 1 is attached to theback surface of the semiconductor wafer 4. The back surface of thesemiconductor wafer 4 means a face opposite to the circuit face (alsoreferred to as non-circuit face, non-electrode-formed face, etc.). Theattaching method is not particularly restricted but a method by pressbonding is preferred. The press bonding is usually performed whilepressing with a pressing means such as a pressing roll.

(Dicing Step)

Next, as shown in FIG. 2B, the semiconductor wafer 4 is diced. Thereby,the semiconductor wafer 4 is cut into a prescribed size andindividualized (is formed into small pieces) to produce semiconductorchips 5. The dicing is performed according to a normal method from thecircuit face side of the semiconductor wafer 4, for example. Moreover,the present step can adopt, for example, a cutting method calledfull-cut that forms a slit reaching the dicing tape-integrated film forsemiconductor back surface 1. The dicing apparatus used in the presentstep is not particularly restricted, and a conventionally knownapparatus can be used. Further, since the semiconductor wafer 4 isadhered and fixed by the dicing tape-integrated film for semiconductorback surface 1 having the film for semiconductor back surface, chipcrack and chip fly can be suppressed, as well as the damage of thesemiconductor wafer 4 can also be suppressed. In this regard, when thefilm for semiconductor back surface 2 is formed of a resin compositioncontaining an epoxy resin, generation of adhesive extrusion from theadhesive layer of the film for semiconductor back surface can besuppressed or prevented at the cut surface even when it is cut bydicing. As a result, re-attachment (blocking) of the cut surfacesthemselves can be suppressed or prevented and thus the picking-up to bementioned below can be further conveniently performed.

In the semiconductor device producing process of the invention, thecutting depth in dicing is so controlled as to fall within a rangeoverstepping the side 32 a of the pressure-sensitive adhesive layer 32that faces (contacts) the film for semiconductor back surface 2 and notreaching the side 32 b thereof that faces (contacts) the base material31. Heretofore, in dicing, the semiconductor wafer is cut to the depthto reach the base material to secure the production margin. However, inthe invention using the integrated film 1, the production margin can bewell secured by cutting to the depth reaching the pressure-sensitiveadhesive layer (not reaching base material). Accordingly, the generationof the cutting dust to be caused by cutting the base material 31 can beprevented and, as a result, semiconductor devices of high reliabilitycan be efficiently produced by preventing the generation of burr aroundsemiconductor chips while keeping the good dicing property of the film1.

The cutting depth is not specifically defined so far as it falls withinthe range overstepping the upper surface 32 a of the pressure-sensitiveadhesive layer 32 and not reaching the lower surface 32 b thereof.However, in the dicing, it is preferable that the cutting depth is sodefined as to fall within a range of from 10% to 70%, more preferablywithin a range of from 15% to 65%, even more preferably within a rangeof from 20% to 60%, of the thickness of the pressure-sensitive adhesivelayer 32 from the surface 32 a of the pressure-sensitive adhesive layer32 that faces the film for semiconductor back surface 2. When thecutting depth is controlled to fall within the above-mentioned range,then the cutting to reach the base material may be prevented even thoughthe cutting depth accuracy fluctuation of various dicing machines istaken into consideration, and therefore the production process of theinvention can readily accept various changes in production lines withpreventing deep cutting to reach the base material, and in addition, theproduction process of the invention in which the cutting depth iscontrolled as above can well secure the production margin in dicing andcan therefore prevent generation of various failures such as dicingfailure, etc.

In the case where the dicing tape-integrated film for semiconductor backsurface 1 is expanded, the expansion can be performed using aconventionally known expanding apparatus. The expanding apparatus has adoughnut-shaped outer ring capable of pushing the dicing tape-integratedfilm for semiconductor back surface 1 downward through a dicing ring andan inner ring which has a diameter smaller than the outer ring andsupports the dicing tape-integrated film for semiconductor back surface.Owing to the expanding step, it is possible to prevent the damage ofadjacent semiconductor chips through contact with each other in thepicking-up step to be mentioned below.

(Picking-Up Step)

In order to collect the semiconductor chip 5 that is adhered and fixedto the dicing tape-integrated film for semiconductor back surface 1,picking-up of the semiconductor chip 5 is performed as shown in FIG. 2Cto peel the semiconductor chip 5 together with the film forsemiconductor back surface 2 from the dicing tape 3. The method ofpicking-up is not particularly restricted, and conventionally knownvarious methods can be adopted. For example, there may be mentioned amethod including pushing up each semiconductor chip 5 from the basematerial 31 side of the dicing tape-integrated film for semiconductorback surface 1 with a needle and picking-up the pushed semiconductorchip 5 with a picking-up apparatus. In this regard, the back surface ofthe picked-up semiconductor chip 5 is protected with the film forsemiconductor back surface 2.

(Flip Chip Connection Step)

The picked-up semiconductor chip 5 is fixed to an adherend 6 such as asubstrate by a flip chip bonding method (flip chip mounting method) asshown in FIG. 2D. Specifically, the semiconductor chip 5 is fixed to theadherend 6 according to a usual manner in a form where the circuit face(also referred to as a front face, circuit pattern-formed face,electrode-formed face, etc.) of the semiconductor chip 5 is opposed tothe adherend 6. For example, the bump 51 formed at the circuit face sideof the semiconductor chip 5 is brought into contact with a conductivematerial 61 (such as solder) for conjunction attached to a connectingpad of the adherend 6 and the conductive material 61 is melted underpressing, whereby electric connection between the semiconductor chip 5and the adherend 6 can be secured and the semiconductor chip 5 can befixed to the adherend 6 (flip chip bonding step). On this occasion, gapsare formed between the semiconductor chip 5 and the adherend 6 and thedistance between the gaps is generally about 30 μm to 300 μm. In thisregard, after the flip chip bonding (flip chip connecting) of thesemiconductor chip 5 on the adherend 6, it is important that theopposing faces of the semiconductor chip 5 and the adherend 6 and thegaps are washed and an encapsulating material (such as an encapsulatingresin) is then filled into the gaps to perform encapsulation.

As the adherend 6, various substrates such as lead frames and circuitboards (such as wiring circuit boards) can be used. The material of thesubstrates is not particularly restricted and there may be mentionedceramic substrates and plastic substrates. Examples of the plasticsubstrates include epoxy substrates, bismaleimide triazine substrates,and polyimide substrates.

In the flip chip bonding step, the material of the bump and theconductive material is not particularly restricted and examples thereofinclude solders (alloys) such as tin-lead-based metal materials,tin-silver-based metal materials, tin-silver-copper-based metalmaterials, tin-zinc-based metal materials, and tin-zinc-bismuth-basedmetal materials, and gold-based metal materials and copper-based metalmaterials.

Incidentally, in the flip chip bonding step, the conductive material ismelted to connect the bump at the circuit face side of the semiconductorchip 5 and the conductive material on the surface of the adherend 6. Thetemperature at the melting of the conductive material is usually about260° C. (e.g., 250° C. to 300° C.). The dicing tape-integrated film forsemiconductor back surface of the invention can be made to have thermalresistance capable of enduring the high temperature in the flip chipbonding step by forming the film for semiconductor back surface with anepoxy resin or the like.

In the present step, it is preferred to wash the opposing face(electrode-formed face) between the semiconductor chip 5 and theadherend 6 and the gaps. The washing liquid to be used at the washing isnot particularly restricted and examples thereof include organic washingliquids and aqueous washing liquids. The film for semiconductor backsurface in the dicing tape-integrated film for semiconductor backsurface of the invention has solvent resistance against the washingliquid and has substantially no solubility to these washing liquid.Therefore, as mentioned above, various washing liquids can be employedas the washing liquid and the washing can be achieved by anyconventional method without requiring any special washing liquid.

Next, an encapsulation step is performed for encapsulating the gapsbetween the flip chip-bonded semiconductor chip 5 and the adherend 6.The encapsulation step is performed using an encapsulating resin. Theencapsulation conditions on this occasion are not particularlyrestricted but the curing of the encapsulating resin is usually carriedout at 175° C. for 60 seconds to 90 seconds. However, in the invention,without limitation thereto, the curing may be performed at a temperatureof 165 to 185° C. for several minutes, for example. By the thermaltreatment in this step, not only the encapsulating resin but also thefilm for semiconductor back surface 2 is also thermally cured at thesame time. Accordingly, both the encapsulating resin and the film forsemiconductor back surface 2 are cured and shrunk with the procedure ofthe thermal curing. As a result, the stress to be given to thesemiconductor chip 5 owing to the curing shrinkage of the encapsulatingresin can be cancelled or relaxed through curing shrinkage of the filmfor semiconductor back surface 2. Moreover, in the step, the film forsemiconductor back surface 2 can be completely or almost completelythermally cured and can be attached to the back surface of thesemiconductor element with excellent close adhesiveness. Further, thefilm for semiconductor back surface 2 according to the invention can bethermally cured together with the encapsulating material in theencapsulation step even when the film is in an uncured state, so that itis not necessary to newly add a step for thermal curing of the film forsemiconductor back surface 2.

The encapsulating resin is not particularly restricted as long as thematerial is a resin having an insulating property (an insulating resin)and may be suitably selected and used among known encapsulatingmaterials such as encapsulating resins. The encapsulating resin ispreferably an insulating resin having elasticity. Examples of theencapsulating resin include resin compositions containing an epoxyresin. As the epoxy resin, there may be mentioned the epoxy resinsexemplified in the above. Furthermore, the encapsulating resin composedof the resin composition containing an epoxy resin may contain athermosetting resin other than an epoxy resin (such as a phenol resin)or a thermoplastic resin in addition to the epoxy resin. Incidentally, aphenol resin can be utilized also as a curing agent for the epoxy resinand, as such a phenol resin, there may be mentioned phenol resinsexemplified in the above.

According to the semiconductor device (flip chip-mounted semiconductordevice) manufactured using the dicing tape-integrated film forsemiconductor back surface 1 or the film for semiconductor back surface2, the film for semiconductor back surface is attached to the backsurface of the semiconductor chip, and therefore, laser marking can beapplied with excellent visibility. In particular, even when the markingmethod is a laser marking method, laser marking can be applied with anexcellent contrast ratio, and it is possible to observe various kinds ofinformation (for example, literal information and graphical information)applied by laser marking with good visibility. At the laser marking, aknown laser marking apparatus can be utilized. Moreover, as the laser,it is possible to utilize various lasers such as a gas laser, asolid-state laser, and a liquid laser. Specifically, as the gas laser,any known gas lasers can be utilized without particular limitation but acarbon dioxide laser (CO₂ laser) and an excimer laser (ArF laser, KrFlaser, XeCl laser, XeF laser, etc.) are suitable. As the solid-statelaser, any known solid-state lasers can be utilized without particularlimitation but a YAG laser (such as Nd:YAG laser) and a YVO₄ laser aresuitable.

Since the semiconductor device produced using the dicing tape-integratedfilm for semiconductor back surface 1 or the film for semiconductor backsurface 2 of the invention is a semiconductor device mounted by the flipchip mounting method, the device has a thinned and miniaturized shape ascompared with a semiconductor device mounted by a die-bonding mountingmethod. Thus, the semiconductor devices can be suitably employed asvarious electronic devices and electronic parts or materials and membersthereof. Specifically, as the electronic devices in which the flipchip-mounted semiconductor devices of the invention are utilized, theremay be mentioned so-called “mobile phones” and “PHS”, small-sizedcomputers [e.g., so-called “PDA” (handheld terminals), so-called“notebook-sized personal computer”, so-called “Net Book (trademark)”,and so-called “wearable computers”, etc.], small-sized electronicdevices having a form where a “mobile phone” and a computer areintegrated, so-called “Digital Camera (trademark)”, so-called “digitalvideo cameras”, small-sized television sets, small-sized game machines,small-sized digital audio players, so-called “electronic notepads”,so-called “electronic dictionary”, electronic device terminals forso-called “electronic books”, mobile electronic devices (portableelectronic devices) such as small-sized digital type watches, and thelike. Needless to say, electronic devices (stationary type ones, etc.)other than mobile ones, e.g., so-called “desktop personal computers”,thin type television sets, electronic devices for recording andreproduction (hard disk recorders, DVD players, etc.), projectors,micromachines, and the like may be also mentioned. In addition,electronic parts or materials and members for electronic devices andelectronic parts are not particularly restricted and examples thereofinclude parts for so-called “CPU” and members for various memory devices(so-called “memories”, hard disks, etc.).

EXAMPLES

The following will illustratively describe preferred Examples of theinvention in detail. However, the invention is not limited to thefollowing Examples unless it exceeds the gist thereof. Moreover, part ineach example is a weight standard unless otherwise stated.

Example 1 Preparation of Film for Semiconductor Back Surface

113 parts of an epoxy resin (trade name “EPICOAT 1004” manufactured byJER Co., Ltd.), 121 parts of a phenolic resin (trade name “MILEX XLC-4L”manufactured by Mitsui Chemicals, Inc.), 246 parts of sphere silica(trade name “SO-25R” manufactured by Admatechs Co., Ltd.), 5 parts ofDye 1 (trade name “OIL GREEN 502” manufactured by Orient ChemicalIndustries Co., Ltd.), and 5 parts of Dye 2 (trade name “OIL BLACK BS”manufactured by Orient Chemical Industries Co., Ltd.) based on 100 partsof an acrylate-based polymer (trade name “PARACRON W-197CM” manufacturedby Negami Chemical Industrial Co., Ltd.) containing ethyl acrylate andmethyl methacrylate as main components were dissolved in methyl ethylketone to prepare a solution of a pressure-sensitive adhesivecomposition having a solid concentration of 23.6% by weight.

The solution of the pressure-sensitive adhesive composition was appliedonto a releasably treated film, as a release liner (separator), composedof a polyethylene terephthalate film having a thickness of 50 μm, whichhad been subjected to a silicone-releasing treatment, and then dried at130° C. for 2 minutes to prepare a film for semiconductor back surfacehaving a thickness (average thickness) of 20 μm.

Preparation of Dicing Tape-Integrated Film for Semiconductor BackSurface

Using a hand roller, the film for semiconductor back surface wasattached to the pressure-sensitive adhesive layer of a dicing tape(trade name “V-8-T” manufactured by Nitto Denko Co., Ltd.; averagethickness of the base material, 65 μm; average thickness of thepressure-sensitive adhesive layer, 20 μm) to prepare a dicingtape-integrated film for semiconductor back surface.

Example 2 Preparation of Film for Semiconductor Back Surface

A film for semiconductor back surface having a thickness (averagethickness) of 20 μm was prepared according to the same process as inExample 1.

Preparation of Dicing Tape-Integrated Film for Semiconductor BackSurface

Using a hand roller, the film for semiconductor back surface wasattached to the pressure-sensitive adhesive layer of a dicing tape(trade name “V-8-T” manufactured by Nitto Denko Co., Ltd.; averagethickness of the base material, 65 μm; average thickness of thepressure-sensitive adhesive layer, 30 μm) to prepare a dicingtape-integrated film for semiconductor back surface.

Example 3 Preparation of Film for Semiconductor Back Surface

A film for semiconductor back surface having a thickness (averagethickness) of 20 μm was prepared according to the same process as inExample 1.

Preparation of Dicing Tape-Integrated Film for Semiconductor BackSurface

Using a hand roller, the film for semiconductor back surface wasattached to the pressure-sensitive adhesive layer of a dicing tape(trade name “V-8-T” manufactured by Nitto Denko Co., Ltd.; averagethickness of the base material, 65 μm; average thickness of thepressure-sensitive adhesive layer, 40 μm) to prepare a dicingtape-integrated film for semiconductor back surface.

Comparative Example 1 Preparation of Film for Semiconductor Back Surface

A film for semiconductor back surface having a thickness (averagethickness) of 20 μm was prepared according to the same process as inExample 1.

Preparation of Dicing Tape-Integrated Film for Semiconductor BackSurface

Using a hand roller, the film for semiconductor back surface wasattached to the pressure-sensitive adhesive layer of a dicing tape(trade name “V-8-T” manufactured by Nitto Denko Co., Ltd.; averagethickness of the base material, 65 μm; average thickness of thepressure-sensitive adhesive layer, 10 μm) to prepare a dicingtape-integrated film for semiconductor back surface.

Comparative Example 2 Preparation of Film for Semiconductor Back Surface

A film for semiconductor back surface having a thickness (averagethickness) of 20 μm was prepared according to the same process as inExample 1.

Preparation of Dicing Tape-Integrated Film for Semiconductor BackSurface

Using a hand roller, the film for semiconductor back surface wasattached to the pressure-sensitive adhesive layer of a dicing tape(trade name “V-8-T” manufactured by Nitto Denko Co., Ltd.; averagethickness of the base material, 65 μm; average thickness of thepressure-sensitive adhesive layer, 50 μm) to prepare a dicingtape-integrated film for semiconductor back surface.

(Evaluation)

The dicing tape-integrated films for semiconductor back surface preparedin Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated forthe dicing property and the picking-up property thereof according to themethod mentioned below. The results are shown in Table 1.

<Evaluating Method of Dicing Property/Picking-Up Property>

Using the dicing tape-integrated film for semiconductor back surface ofExamples 1 to 3 and Comparative Examples 1 and 2, a semiconductor waferwas actually diced in the manner mentioned below to thereby evaluate thedicing property of the film. Subsequently, the film was evaluated forthe peeling easiness. In that manner, the dicing tape-integrated filmfor semiconductor back surface was evaluated for the dicing capabilityand the picking-up capability thereof.

A semiconductor wafer (diameter: 8 inches, thickness: 0.6 mm; a siliconmirror wafer) was subjected to a back surface polishing treatment and amirror wafer having a thickness of 0.2 mm was used as a workpiece. Afterthe separator was peeled from the dicing tape-integrated film forsemiconductor back surface, the mirror wafer (workpiece) was attachedonto the film for semiconductor back surface by roller press-bonding at70° C. With that, the workpiece was diced in such a manner that thecutting depth by the dicing blade could reach the center of thepressure-sensitive adhesive layer of the dicing tape-integrated film.The dicing was performed as full cut so as to be a chip size of 10 mmsquare. The semiconductor wafer polishing condition, the attachingcondition and the dicing condition are as follows.

(Conditions for Semiconductor Wafer Grinding)

Grinding apparatus: a trade name “DFG-8560” manufactured by DISCOCorporation

Semiconductor wafer: 8 inch diameter (back surface was ground so as tobe until a thickness of 0.2 mm from a thickness of 0.6 mm)

(Attaching Conditions)

Attaching apparatus: a trade name “MA-3000III” manufactured by NittoSeiki Co., Ltd.

Attaching speed: 10 mm/min

Attaching pressure: 0.15 MPa

Stage temperature at the time of attaching: 70° C.

(Dicing Conditions)

Dicing apparatus: a trade name “DFD-6361” manufactured by DISCOCorporation

Dicing ring: “2-8-1” (manufactured by DISCO Corporation)

Dicing speed: 30 mm/sec

Dicing blade:

Z1; “2030-SE 27HCDD” manufactured by DISCO Corporation

Z2; “2030-SE 27HCBB” manufactured by DISCO Corporation

Dicing blade rotation speed:

Z1; 40,000 r/min

Z2; 45,000 r/min

Blade height:

Z1: 110 μm from the wafer surface

Z2: center of the pressure-sensitive adhesive layer of the dicingtape-integrated film

Cutting method: step cutting

Wafer chip size: 10.0 mm square

(Dicing Property Evaluation)

In the dicing operation, the workpiece chips were evaluated for thedicing aptitude as to whether or not they were well diced with nocontamination with base material-derived impurities (burr) on the sidefaces of the workpiece chips and with neither cracking nor breakage ofthe diced workpiece chips, according to the process mentioned below,

(Burr Evaluation)

After picked up, the sides of the chips with the film for semiconductorback surface attached thereto (four sides of all 100 chips) wereobserved with a microscope (magnification: 20-power). The samples thathad been well diced with no burr under the above-mentioned dicingcondition were ranked “Good”; and the samples that could not be welldiced but had burr around them were ranked “Poor”.

(Breakage/Cracking Evaluation)

Like those in burr evaluation, the sides of the chips with the film forsemiconductor back surface attached thereto (four sides of all 100chips) were observed with a microscope (magnification: 20-power). Thesamples that had not been broken or cracked on the sides thereof wereranked “Good”; and the samples that had been broken or cracked on thesides thereof were ranked “Poor”.

(Picking-Up Aptitude Evaluation)

Next, the workpiece chips obtained by dicing were picked up from thepressure-sensitive adhesive layer of the dicing tape together with thefilm for semiconductor back surface by pushing up the chips from thedicing tape side of the dicing tape-integrated film for semiconductorback surface with a needle, thereby giving the workpiece chips of whichthe back surface was protected with the film for semiconductor backsurface. The picking-up success ratio (%) of the chips (400 pieces intotal) on this occasion was determined to evaluate the picking-upproperty. Therefore, the picking-up property is better when thepicking-up ratio is closer to 100%.

The picking-up condition is as follows.

(Semiconductor Wafer Picking-Up Condition)

Picking-up apparatus: trade name “SPA-300” manufactured by Shinkawa Co.,Ltd.

Number of picking-up needles: 9 needles

Pushing-up speed of needle: 20 mm/s

Pushing-up distance of needle: 500 μm

Picking-up time: 1 second

Dicing tape-expanding amount: 3 mm

TABLE 1 Thickness of Pressure-sensitive Dicing Property Picking-Upadhesive Layer breakage, Property [μm] burr cracking [%] Example 1 20Good Good 100 Example 2 30 Good Good 100 Example 3 40 Good Good 100Comparative 10 Poor Good 100 Example 1 Comparative 50 Good Poor 70Example 2

From Table 1, it can be seen that, when the dicing tape-integrated filmfor semiconductor back surface of Examples 1 to 3 was used, theworkpiece chips obtained by dicing were neither cracked nor broken andhad no base material-derived burr around the side surfaces thereof, andthat the dicing tape-integrated film had good dicing property. Inaddition, it is further known that, in picking up them, the diced chipsexhibited good peeling easiness. On the other hand, the dicingtape-integrated film for semiconductor back surface of ComparativeExample 1 produced burr around the sides of the diced workpiece chipsthough its picking-up property was good, and therefore, the dicingproperty of the dicing tape-integrated film was poor. When the dicingtape-integrated film for semiconductor back surface of ComparativeExample 2 was used in dicing, the diced workpiece chips were cracked orbroken, or that is, the dicing property of the dicing tape-integratedfilm was poor, and in addition, the picking-up property thereof was alsopoor.

While the present invention has been described in detail and withreference to specific embodiments thereof, it will be apparent to oneskilled in the art that various changes and modifications can be madetherein without departing from the scope thereof.

This application is based on Japanese patent application No. 2010-170933filed Jul. 29, 2010, the entire contents thereof being herebyincorporated by reference.

1. A dicing tape-integrated film for semiconductor back surfacecomprising: a dicing tape comprising a base material and apressure-sensitive adhesive layer laminated in this order, and a filmfor semiconductor back surface provided on the pressure-sensitiveadhesive layer of the dicing tape, wherein the pressure-sensitiveadhesive layer has a thickness of from 20 μm to 40 μm.
 2. The dicingtape-integrated film for semiconductor back surface according to claim1, wherein the ratio x/y is from 1 to 4, in which x is the thickness ofthe pressure-sensitive adhesive layer and y is a thickness of the filmfor semiconductor back surface.
 3. The dicing tape-integrated film forsemiconductor back surface according to claim 1, wherein the ratio z/yis from 1.5 to 25, in which y is a thickness of the film forsemiconductor back surface and z is a thickness of the dicing tape. 4.The dicing tape-integrated film for semiconductor back surface accordingto claim 2, wherein the ratio z/y is from 1.5 to 25, in which y is athickness of the film for semiconductor back surface and z is athickness of the dicing tape.
 5. A process for producing a semiconductordevice using the dicing tape-integrated film for semiconductor backsurface according to claim 1, the process comprising: attaching asemiconductor wafer onto the film for semiconductor back surface of thedicing tape-integrated film for semiconductor back surface, dicing thesemiconductor wafer to form a semiconductor chip in which a cuttingdepth is so controlled as to fall within a range overstepping one sideof the pressure-sensitive adhesive layer that faces the film forsemiconductor back surface and not reaching the other side of thepressure-sensitive adhesive layer that faces the base material, peelingthe semiconductor chip from the pressure-sensitive adhesive layer of thedicing tape together with the film for semiconductor back surface, andflip chip-connecting the semiconductor chip onto an adherend.
 6. Theprocess for producing a semiconductor device according to claim 5,wherein the ratio x/y is from 1 to 4, in which x is the thickness of thepressure-sensitive adhesive layer and y is a thickness of the film forsemiconductor back surface.
 7. The process for producing a semiconductordevice according to claim 5, wherein the ratio z/y is from 1.5 to 25, inwhich y is a thickness of the film for semiconductor back surface and zis a thickness of the dicing tape.
 8. The process for producing asemiconductor device according to claim 6, wherein the ratio z/y is from1.5 to 25, in which y is a thickness of the film for semiconductor backsurface and z is a thickness of the dicing tape.
 9. The process forproducing a semiconductor device according to claim 5, wherein thecutting depth in the dicing is so controlled as to fall within a rangeof from 10% to 70% of the thickness of the pressure-sensitive adhesivelayer from the side of the adhesive layer that faces the film forsemiconductor back surface.
 10. The process for producing asemiconductor device according to claim 6, wherein the cutting depth inthe dicing is so controlled as to fall within a range of from 10% to 70%of the thickness of the pressure-sensitive adhesive layer from the sideof the adhesive layer that faces the film for semiconductor backsurface.
 11. The process for producing a semiconductor device accordingto claim 7, wherein the cutting depth in the dicing is so controlled asto fall within a range of from 10% to 70% of the thickness of thepressure-sensitive adhesive layer from the side of the adhesive layerthat faces the film for semiconductor back surface.
 12. The process forproducing a semiconductor device according to claim 8, wherein thecutting depth in the dicing is so controlled as to fall within a rangeof from 10% to 70% of the thickness of the pressure-sensitive adhesivelayer from the side of the adhesive layer that faces the film forsemiconductor back surface.